The present invention relates to a process for refrigeration using a chlorine-free fluorocarbon refrigerant.
A refrigeration system is designed to produce a cooling effect and is used for air conditioning buildings and in the treatment transportation and preservation of foods. During a refrigeration cycle the refrigerant undergoes a physical change resulting in a cooling effect, for example, a change from the liquid state to the vapor state. A simple refrigeration system is generally closed and consists of four major components, namely an evaporator, a compressor, a condenser and an expansion device. During the refrigeration cycle the refrigerant in liquid form leaves the condenser and passes through the expansion device where the pressure is lowered. The refrigerant passes into the evaporator where heat is absorbed and the refrigerant evaporates. The refrigerant leaves the evaporator as vapor and enters the compressor where it is compressed to a superheated vapor before passing into the condenser to complete the cycle, which is repeated continuously.
The most widely used refrigerants are known as chlorofluorocarbons (CFCs). These compounds are fully halogenated, very stable, have low toxicity and excellent thermodynamic performance in use. Unfortunately, CFCs, because of their stability, have long atmospheric lifetimes. It has been postulated that when these materials decompose in the stratosphere, under the influence of ultraviolet radiation, they release chlorine atoms which, it is theorized, react with the ozone thus depleting this protective layer which shields the earth from harmful ultraviolet radiation.
There is a need for fluorocarbon refrigerants that are substantially chlorine-free and environmentally safe, non-flammable, have low toxicity and excellent thermodynamic properties, especially its refrigeration capacity at a given evaporator temperature, and a high coefficient of performance.